Purification and characterization of an esterase involved in poly(vinyl alcohol) degradation by Pseudomonas vesicularis PD.

An esterase catalyzing the hydrolysis of acetyl ester moieties in poly(vinyl alcohol) was purified 400-fold to electrophoretic homogeneity from the cytoplasmic fraction of Pseudomonas vesicularis PD, which was capable of assimilating poly(vinyl alcohol) as the sole carbon and energy source. The purified enzyme was a homodimeric protein with a molecular mass of 80 kDa and the isoelectric point was 6.8. The pH and temperature optima of the enzyme were 8.0 and 45 degrees C. The enzyme catalyzed the hydrolysis of side chains of poly(vinyl alcohol), short-chain p-nitrophenyl esters, 2-naphthyl acetate, and phenyl acetate, and was slightly active toward aliphatic esters. The enzyme was also active toward the enzymatic degradation products, acetoxy hydroxy fatty acids, of poly(vinyl alcohol). The K(m) and Vmax of poly(vinyl alcohol) (degree of polymerization, 500; saponification degree, 86.5-89.0 mol%) and p-nitrophenyl acetate were 0.381% (10.6 mM as acetyl content in the polymer) and 2.56 microM, and 6.52 and 12.6 mumol/min/mg, respectively. The enzyme was strongly inhibited by phenylmethylsulfonyl fluoride and diisopropyl fluorophosphate at a concentration of 5 mM, which indicated that the enzyme was a serine esterase. The pathway for the metabolism of poly(vinyl alcohol) is also discussed.

[A single session of transurethral microwave thermotherapy for benign prostatic hyperplasia].

A single session of transurethral microwave thermotherapy using Prostatron (Technomed International, France) was performed in 20 patients with benign prostatic hyperplasia, and the clinical efficacy of this modality was evaluated by analysing the subjective and objective responses following the treatment. 1,296 MHz microwaves are delivered to the prostate by an antenna placed in a 20 Fr urethral balloon catheter equipped with a cooling system for preservation of the urethral mucosa. The treatment was performed in a single session for an hour on an outpatient basis. The clinical efficacy was evaluated by a total score of subjective symptoms and objective findings including residual urine and average flow rate, 8 weeks after the treatment. Reduction of subjective symptom score was observed in 26 cases (86.7%), and that of objective findings in 21 (70%). When 25% or more decrease of the total score was defined as good, the overall good result including subjective and objective responses was seen in 24 cases (80%). During the treatment and follow-up period, no severe adverse effect was detected. In conclusion, a single session of thermotherapy by Prostatron is a safe and useful modality as a non-surgical treatment performed on an outpatient basis for benign prostatic hyperplasia.

[Outpatient treatment with extracorporeal lithotriptor for renal and ureteral stones].

Between April 1989 and December 1989, extracorporeal shock wave lithotripsy (ESWL) was performed on 78 outpatients using the EDAP LT-01 device without anesthesia. The locations of total 83 stones were renal pelvis and calyx (45), upper ureter (26) and lower ureter (12). Of the cases with renal stones, 28 (62%) were free of stones, and 8 (18%) had fragments 4 mm in size or less. The over-all successful rate obtained by combining these categories were 80% in renal stones, 81% in upper ureteral stones, and 92% in lower ureteral stones. As complications, gross hematuria, pain which required analgesics, fever of 38 degrees C or higher and vomiting were seen. However, no serious complications were observed.